Matlab licensing error -9.57.I use my university licence but failed to install this for several times.I activate matlab.But it frequently shows this tab.

[Walter Roberson]

Are you administrator of the computer? If so then I recommend deleting

C:\Users\Administrator\AppData\Roaming\MathWorks\MATLAB\R2021a_licenses (and any files there if it is a directory)

C:\Program Files\MATLAB\R2021a\licenses\license_DESKTOP-C681QK4_40981619_R2021a.lic

and then re-activating.

You should probably not activate as Administrator.